Rains heavily on squads, say (5)
I believe the answer is:
teems
'rains heavily' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for teems that I've seen before include "Pours down" , "Buckets down" , "Abounds, swarms" , "Rains heavily" .)